I am thinking and thinking and want to go this direction. Here's an odd question, perhaps. I see that most use a plug to attach power to the CP, is there a reason NOT to hardwire the box to a cable/line that would then plug into a 30/40/50 amp outlet. I am thinking of a dryer. It is hardwired and you simply plug it in. Thoughts?

That's what I did - I figured it's much easier to drill a small 3/4"-1" hole for a liquid tight connector than cutting a big hole for a panel mounted plug, and cheaper too.

Downside - I'm not really sure there is one. I wonder how often the folks with the plug end on their panels actually unplug them, or if they are essentially hard wired. I suppose if your outlet is inconvenient to get to, unplugging at the panel makes sense. My outlet is about 4' away so easy day.

Got the new contactor wired and installed. The safe start interlock worked exactly as described and the new contactor as well. My panel finally has life. Unfortunately, there's something wrong and I'm getting stray voltage all over the place. I need to spend some more time troubleshooting but there's a good chance I'll be throwing my issues up here soon in search of your help. Fingers crossed.

So for some reason two of my switches weren't working right. Pulled them and tested each operation individually and they seem to work fine, which tells me I have a bad wire somewhere.

Also, with the switch that I use to run my contactors between the SSR and the receptacles - if I take a voltage reading across the switch output (with the switch open) to either Hot A or Hot B I get somewhere around 100 volts. It seems as though my output line is running to neutral through the coil of the contactor. Is it normal to get those kinds of leakage currents through the coil when it's not engaged?

So here's a picture to help - if I take a reading from 24 to black (Hot A), with the switch not depressed (23/24 is NO, so no power), I get a voltage reading. If I pull the neutral from the coil of the contactor, I get no voltage reading. Is this normal, or is there a problem with my contactors?

So here's a picture to help - if I take a reading from 24 to black (Hot A), with the switch not depressed (23/24 is NO, so no power), I get a voltage reading. If I pull the neutral from the coil of the contactor, I get no voltage reading. Is this normal, or is there a problem with my contactors?

That is normal. Nothing wrong with that.

BTW: Do you have a diagram showing the total wiring plan? The safe start interlock setup is what I'd like to see.